| |
Records |
Links |
|
Author |
Zhang, Zijing; Zhang, Jianlong; Wu, Long; Zhang, Yong; Zhao, Yuan; Su, Jianzhong |
|
| |
Title |
Photon-counting chirped amplitude modulation lidar using a smart premixing method |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Opt. Lett. |
Abbreviated Journal |
Opt. Lett. |
|
| |
Volume |
38 |
Issue |
21 |
Pages |
4389-4392 |
|
| |
Keywords  |
photon-counting detector, lidar, Geiger mode APD, Geiger mode lidar |
|
| |
Abstract |
We proposed a new premixing method for photon-counting chirped amplitude modulation lidar (PCCAML). Earlier studies used the counting results of the returned signal detected by a Geiger mode avalanche photodiode detector (Gm-APD) to mix with the reference signal, called the postmixing method. We use an alternative method known as the premixing method, in which the reference signal is used to directly modulate the sampling gate width of the Gm-APD, and the mixing of the returned signal and the reference signal is completed before the Gm-APD. This premixing method is more flexible and may perform better than the postmixing method in terms of signal-to-noise ratio by cutting down a separated mixer commonly used in the postmixing lidar system. Furthermore, this premixing method lowers the demand for the sampling frequency of the Gm-APD. It allows the use of a much wider modulation bandwidth to improve the range accuracy and resolution. To the best of our knowledge, this is the first report to use the premixing method in the PCCAML system, which will benefit future lidar applications. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1006 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Kataoka, T; Kajikawa, K.; Kitagawa, J.; Kadoya, Y; Takemura, Y. |
|
| |
Title |
Improved sensitivity of terahertz detection by GaAs photoconductive antennas excited at 1560 nm |
Type |
Journal Article |
| |
Year |
2010 |
Publication |
Appl. Phys. Lett. |
Abbreviated Journal |
Appl. Phys. Lett. |
|
| |
Volume |
97 |
Issue |
|
Pages |
201110 (1-3) |
|
| |
Keywords |
photoconductive antenna (PCA) |
|
| |
Abstract |
The terahertz detection by photoconductive antennas (PCAs) based on low-temperature grown (LTG) GaAs with 1.5 μm pulse excitation was revisited. We found that the detection efficiency can be improved by a factor of 10 (20 dB) by reducing the excitation spot size and the gap length of the PCA, maintaining the low noise feature of the PCA on LTG GaAs. As a result, the signal-to-noise ratio higher than 50 dB was obtained at a reasonable incident power of 9.5 mW, suggesting that the scheme is promising for the detection of terahertz waves in practical time domain systems. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
904 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Sahu, Mitrabhanu; Bae, Myung-Ho; Rogachev, Andrey; Pekker, David; Wei, Tzu-Chieh; Shah, Nayana; Goldbart, Paul M.; Bezryadin, Alexey |
|
| |
Title |
Individual topological tunnelling events of a quantum field probed through their macroscopic consequences |
Type |
Journal Article |
| |
Year |
2009 |
Publication |
Nature Phys. |
Abbreviated Journal |
Nature Phys. |
|
| |
Volume |
5 |
Issue |
|
Pages |
503-508 |
|
| |
Keywords |
phase slips, superconducting nanowires |
|
| |
Abstract |
Phase slips are topological fluctuations that carry the superconducting order-parameter field between distinct current-carrying states. Owing to these phase slips, superconducting nanowires acquire electrical resistance. In such wires, it is well known that at higher temperatures phase slips occur through the process of thermal barrier-crossing by the order-parameter field. At low temperatures, the general expectation is that phase slips should proceed through quantum tunnelling events, which are known as quantum phase slips. However, resistive measurements have produced evidence both for and against the occurrence of quantum phase slips. Here, we report evidence for the observation of individual quantum phase-slip events in homogeneous ultranarrow wires at high bias currents. We accomplish this through measurements of the distribution of switching currents for which the width exhibits a rather counter-intuitive, monotonic increase with decreasing temperature. Importantly, measurements show that in nanowires with larger critical currents, quantum fluctuations dominate thermal fluctuations up to higher temperatures. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Recommended by Klapwijk |
Approved |
no |
|
| |
Call Number |
|
Serial |
928 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Poglitsch, A.; Waelkens, C.; Geis, N.; Feuchtgruber, H.; Vandenbussche, B.; Rodriguez, L.; Krause, O.; Renotte, E.; van Hoof, C.; Saraceno, P.; Cepa, J.; Kerschbaum, F.; Agnèse, P.; Ali, B.; Altieri, B.; Andreani, P.; Augueres, J.-L.; Balog, Z.; Barl, L.; Bauer, O. H.; Belbachir, N.; Benedettini, M.; Billot, N.; Boulade, O.; Bischof, H.; Blommaert, J.; Callut, E.; Cara, C.; Cerulli, R.; Cesarsky, D.; Contursi, A.; Creten, Y.; De Meester, W.; Doublier, V.; Doumayrou, E.; Duband, L.; Exter, K.; Genzel, R.; Gillis, J.-M.; Grözinger, U.; Henning, T.; Herreros, J.; Huygen, R.; Inguscio, M.; Jakob, G.; Jamar, C.; Jean, C.; de Jong, J.; Katterloher, R.; Kiss, C.; Klaas, U.; Lemke, D.; Lutz, D.; Madden, S.; Marquet, B.; Martignac, J.; Mazy, A.; Merken, P.; Montfort, F.; Morbidelli, L.; Müller, T.; Nielbock, M.; Okumura, K.; Orfei, R.; Ottensamer, R.; Pezzuto, S.; Popesso, P.; Putzeys, J.; Regibo, S.; Reveret, V.; Royer, P.; Sauvage, M.; Schreiber, J.; Stegmaier, J.; Schmitt, D.; Schubert, J.; Sturm, E.; Thiel, M.; Tofani, G.; Vavrek, R.; Wetzstein, M.; Wieprecht, E.; Wiezorrek, E. |
|
| |
Title |
The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory |
Type |
Journal Article |
| |
Year |
2010 |
Publication |
Astron. Astrophys. |
Abbreviated Journal |
A&A |
|
| |
Volume |
518 |
Issue |
|
Pages |
12 |
|
| |
Keywords |
PACS |
|
| |
Abstract |
The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments on ESA's far infrared and submillimetre observatory. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16×25 pixels, each, and two filled silicon bolometer arrays with 16×32 and 32×64 pixels, respectively, to perform integral-field spectroscopy and imaging photometry in the 60-210 μm wavelength regime. In photometry mode, it simultaneously images two bands, 60-85 μm or 85-125 μm and 125-210 μm, over a field of view of ~1.75'× 3.5', with close to Nyquist beam sampling in each band. In spectroscopy mode, it images a field of 47â€ × 47â€, resolved into 5×5 pixels, with an instantaneous spectral coverage of ~1500 km s-1 and a spectral resolution of ~175 km s-1. We summarise the design of the instrument, describe observing modes, calibration, and data analysis methods, and present our current assessment of the in-orbit performance of the instrument based on the performance verification tests. PACS is fully operational, and the achieved performance is close to or better than the pre-launch predictions. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
RPLAB @ gujma @ |
Serial |
694 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Gershenzon, E. M.; Gol'tsman, G. N.; Kagane, M. L. |
|
| |
Title |
Energy spectrum of acceptors in germanium and its response to a magnetic field |
Type |
Journal Article |
| |
Year |
1977 |
Publication |
Sov. Phys. JETP |
Abbreviated Journal |
Sov. Phys. JETP |
|
| |
Volume |
45 |
Issue |
4 |
Pages |
769-776 |
|
| |
Keywords |
p-Ge, photoconductivity, energy spectrum, magnetic field |
|
| |
Abstract |
We investigated the spectrum of the submillimeter photoconductivity of p-Ge at helium temperatures and the effects of a magnetic field up to 40 kOe on the spectrum. A large number of lines of transitions between the excited states of the acceptors was observed, some of the lines were identified, and the energies of a number of spectral levels B, Al, Ga, In, and TI in Ge were identified. The results are compared with calculations and with experimental data obtained from the spectra of the photoexcitation of the ground state of the impurities. Using one transition as an example, we discuss the splitting of the excited states of acceptors in the magnetic field and under uniaxial compression. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1727 |
|
| Permanent link to this record |
